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By William L. Meyer

With high expectations and promises, computers were introduced to the mining industry in the late 1950s and 1960s. Applications spread in the 1970s when capabilities began to catch up to early promises, and people within the industry began to see the benefits of using computers in business and engineering. The 1980s have seen a wide acceptance of computers, both large and small, and the use of computers is accelerating throughout the industry. Computers have changed dramatically over the last 25 years. The power of some microcomputers matches the capabilities of main frame computers from less than 10 years ago. The variety of software on these micros exceeds what is available on many larger computers today. Changes over the next 10 years are likely to be greater than those of the last 10 years. Making use of available computer technology while trying to cope with the rapid changes in this industry will take much effort within mining. To take advantage of existing computers, consider and evaluate: project needs and applications; professional, administrative, and support personnel; computer software and technology; and computer and related hardware. Note that this list is in the order of decreasing importance. These categories are also presented in the order for which organization and solutions should be provided to get the most out of computers. To start with a computer and go up the list has cost many mining companies needless expenditures, wear and tear on personnel, and frustration. It is assumed for this article that the need for computer tools is self evident. You can do without a computer by using the appropriate techniques (manual methods) with any required shortcuts plus a lot of personnel time. Indeed, several companies are doing that as a "solution" to what to do with their excess engineering personnel in these lean times. However, the future may be better served if some of these people could be prepared to handle the applications and technology presently available. People and Problems To present the factors related to turning the computer into a productivity aide, it may be enlightening to examine some common people problems that reduce productivity. The most valuable resource any mining company has is its mining professionals. And, particularly with computers, people either make the successes or create the barriers, not the machines. The following list of people problems (syndromes and complexes) has been amply observed during some 23 years of the author's experience with computers and their applications in mining. Home Grown Syndrome - "Nobody else can really understand my problem or provide `exactly' what I need to solve it." While there may be some truth to this syndrome, it would be an unusual project that cannot be handled with existing solutions for at least 75-80% of the needs. Having a base to build on will also speed the development of any remaining needs. It does not seem justified to start all over for a new application, even if "our problem is unique." Not Invented Here Syndrome - This "justification" for the continued existence and budgets of some groups has various forms: "It wasn't done here so it obviously can't do the project the way I think it should be done"; and, "If it wasn't invented here, it obviously

Jan 11, 1983

By R. J. Roman

Introduction This paper attempts to describe the characteristics of the industrial minerals segment of the minerals industry that make it different from the other segments. Also described are the trends, strengths, and shortcomings in the industrial minerals segment. This may help professionals in the minerals industry determine if there is a place for them in industrial minerals. Industry Overview It is difficult to generalize when describing the industrial minerals industry. Some products, such as cement and potash, are produced exclusively by large, well capitalized and technically sophisticated companies. Others, such as sand and gravel, are generally produced by small, family-owned companies operating on a shoestring budget. Still other products, such as feldspar, are produced by both types of companies. Not only are the companies vastly different, the products and marketing of their products are also different. Industrial mineral products are sold based on their physical characteristics (abrasives), or their chemical characteristics (trona), or both (glass sand). Marketing can be direct by the producing plant, a corporate office handling products form several plants, or through distributors. The geologic, mining, and processing skills needed can be minimal or sophisticated. There can even be large differences in the technical skills needed in two plants producing the same product. One feldspar producer may only need to mine and grind his ore, while another may use a delicate flotation process. One easy generalization is that there are industrial mineral operations in all geographic locations. A second is that industrial minerals offers more opportunities to entrepreneurs than the metals field because of the variety in the sizes and types of operations. Industry Growth Industrial minerals must be considered a mature industry. Consequently, little exciting growth can be expected. Over the past 30 years, industry sales have grown at a rate of 6.2%, compared to a 6.7% growth rate of the GNP (Kliff, 1978). A 3.8% growth rate has been forecast for the remainder of this century. The fortunes of those plants producing a product for local consumption will depend on the prosperity of the local economy. The fortunes of those plants that sell into the national market will depend on their competitiveness in their industry. Major industrial mineral products are shown in Table 1. The first three commodities account for 66% of the industrial minerals market. Typically, deposits of stone, sand and gravel, and the limestone, silica, and clay needed for cement are easy to find and mine. Role of Mining Engineers and Geologists Because a sophisticated techcical knowledge of geology or mining is not required, very few geologists and mining engineers are employed in industrial minerals. Geologists working for these companies function less as geologists than managers and executives dealing with permitting and land acquisition. Likewise, mining is done mostly by open-pit methods. It is generally supervised by an individual experienced in the operation and maintenance of heavy equipment, not a mining engineer trained in rock mechanics or computer methods of mine planning. What of the geologists and mining engineers employed by the industrial minerals industry? Many gained their positions as a result of their experience dealing with the regulatory agencies that control the operations of all mines and mills. Their technical expertise in geology or mining becomes only a side benefit. Finding and mining industrial minerals does not generally require the concentrated efforts of geologists and mining engineers. But the processing of the ores does

Jan 2, 1985

By F. Feichtinger, M. Riess, A. Lammer

Introduction This article discusses the unique range of properties of platinum and its applications as a high technology metal. World reserves of this strategic and precious metal are confined mostly to South Africa and, to a far lesser extent, the Soviet Union. An analysis is given of past trends in world platinum output. The timepath is computed for the world platinum output rate, covering a period of more than 350 years. This is based on the postulate that the industrial conversion of a virgin resource progresses according to a Sigmoid curve. This computation is performed by means of a nonlinear, three-stage optimization model employing a multiform Sigmoid function. Finally, the price dynamics are examined. Platinum is the most important of the group of the platinum metals to which it gives its name. Other platinum group metals are iridium, osmium, palladium, rhodium, and rhutenium. The metals occur in nature in close association and are chemically very similar to each other. Three members of the group - platinum, iridium, and osmium - are the heaviest metals known to man. Platinum's density is 11% heavier than gold and about twice the weight of the same volume of silver or lead. Properties Platinum is a typical grayish-white metal. Its special properties were known 1000 years ago to the American Indian craftsmen of what is now Ecuador and Colombia. From those distant beginnings, platinum is now firmly established as the most precious and distinctive metallic element known to mankind. It is shown in Table 1, platinum has a unique wide range of physical, chemical, and mechanical properties including high melting point, resistance to chemical attack, high catalytic activity, mechanical strength, and malleability. These properties make it indispensable for use in many industries. Application Platinum is first and foremost a high technology metal. During the last few decades, fertile scientific minds searched for and developed widespread cost-effective uses for this precious metal. Its unique properties render it irreplaceable in many key industrial processes. Important major fields of application include: • protection of man's natural environment (pollution control), • defense, • fuel production, • fertilizer manufacture, • glass and glass fiber manufacture, • pollution-free energy generation - replacement of nuclear and fuel operated power plants, • electronics, • dentistry, • medicine, and • jewelry. Besides these industrial markets, platinum is increasingly finding a place in investment portfolios around the world as investors switch from gold and silver holdings to this relatively scarce and strategic commodity. Platinum has a growing popularity among private investors. This is being accelerated by the predicted "big crash" of the US dollar and its associated weak currencies, which American financial analysts are expecting towards the end of the decade. Figure 1 shows the demand for platinum in various applications throughout the western world in 1986. The total demand amounted to 88.6 t (97.6 st) of which autocatalyst usage accounted for 32.8 t (36 st) or 37%, the biggest share. Catalytic converter technology is increasingly centered on rhodium-platinum three-way catalysts. These catalysts are able to deal with all three pollutants - carbon monoxide, hydrocarbons, and nitrogen oxides - in a single catalytic unit. The introduction of these three-way converters will result in a further steep rise in the platinum demand for autocatalysts. Among all the metals used in the antipollution devices for automobiles, platinum remains

Jan 2, 1988

The 1996 Arizona Conference was held in Tucson on Dec. 8 and 9. Attendance was 648, a 12% increase from the 1995 conference. The annual conference is organized by the Arizona Conference Board of Directors, representing SME sections from throughout Arizona and adjacent areas. In addition to those representing mining and processing operations in the Arizona region, the meeting was well attended by interested parties from throughout North America. These included vendors, consultants, academia, research organizations and corporate management. The technical program highlighted the meeting. It consisted of a keynote address and morning and afternoon technical sessions. In the technical sessions, 23 papers were presented by the mining, hydrometallurgical, smelting, geology and mineral-processing divisions. The conference was then capped by a banquet that included a talk by a noted economist. Keynote address The program was kicked off by a keynote address titled "Forecasting for the 105th Congress," by Rep. John Shadegg (R-AZ). He was elected to Arizona's Fourth Congressional District in 1994. Shadegg serves on the House Budget Committee, the Resources Committee and the watchdog Government Reform Committee. He stressed the familiar conservative positions of reducing government spending, balancing the budget and states rights. As a member of the House Resources Committee, Shadegg stated his support for the mining industry. Technical sessions Mining division. Two of the five presentations described developments at two Arizona mining operations. T.J. Swendseid of Phelps Dodge presented a paper titled "New developments at Morenci" and P. Garretson of BHP presented a paper titled "Startup of the Robinson Project." Morenci continues to expand its operation and recently broke records for production. Other developments at Morenci included the completion of a 600-m (2,000-ft) drainage tunnel and stockpile rehandling. In addition, Phelps Dodge moved Morenci's crusher plant. It was completely disassembled and reassembled in just eight days. Another interesting presentation was "Predictive maintenance techniques for large electric shovels at Cyprus Sierrita," presented by T. Ritzel of Cyprus Amax. The presentation described high-technology methods for predicting maintenance problems. These methods included vibration analysis, ultrasonic detection, infrared thermography, electrical measurements and tribology (the science of lubricant evaluation). The benefits of these techniques are reduced downtime of the equipment, as was demonstrated in case studies at the mine. The other presentations were "Introduction to NOSA 5-star safety program," by R. McKinnon, BHP Copper North America, and "A new design guideline for mine sealing," by K. Fuenkajorn, Rock Engineering International. Hydrometallurgical division. The hydrometallurgical session consisted of five papers. These included a presentation titled "Recovery of gold and silver using guanidine-based extractants," by M. Vining of Henkel Corp., Tucson, AZ. In this presentation, guanidine-based extractants LIX-79 and AURIX resin were introduced. LIX-79 was shown to have applications in copper-gold and high silver ores. In ammonia-cyanide leaching, AURIX was shown to be more selective in CIL vs. RIL comparisons. Other papers in the hydrometallurgical division included "Application of cobalt in the copper industry," by J. Hawke, OMG Apex Inc.; "Series parallel conversions and production gains at Cyprus Miami Mining's dump leach and solvent extraction operation," by E. Bilson of Cyprus Amax; "Lead alloy anode corrosion at the San Manuel SXEW tankhouse," by W .M. Gort of BHP Copper and "Hydrometallurgical treatment of copper refinery slimes," by B.C. Wesstrom of Phelps Dodge. Smelting division. Three papers were presented in the smelting division session. These included updates and reports on improvements at the Hayden, Hidalgo and BHP San Manuel smelters. For example, W.A. Dutton of Phelps Dodge presented "Recent improvements at the Hidalgo Smelter." These changes were aimed at reducing environmental emissions and increasing production. They included modifications to the fugitive-gas collection system to reduce particulate emissions, rubber lining the acid plant scrubbers to reduce corrosion and the installation of a cold lime softening system for water treatment. Equally interesting papers were presented by D. Norton of Asarco, Hayden, AZ, in a paper titled "Update of the Hayden smelter process," and by D. Jones of BHP Copper, San Manuel, AZ, in a paper titled "Update on first campaign of the BHP San Manuel Copper." Geology division. The session began with a paper that outlined the progress of an exploration project in South America. "The Pierina exploration project, Ancash Province, Peru" was presented by J.D. Lowell, Lowell Mineral Exploration, Rio Rico, AZ. Another paper was then presented on a copper deposit in Grant County, New Mexico. "Zonation of supergene copper minerals at Hanover Mountain, Grant

Jan 1, 1997

By Anand Kumar, Debasis Deb, A. K. Mishra, M V. N. S. PRASAD.

In the Adriyala project, shield-leg pressure data from all shields and shearer location with time stamp from a mechanized longwall face are monitored and recorded in a surface computer. The data contain random noise due to power failure, leakage of legs, bad sensor readings, and other maintenance or geomechanical problems. An algorithm has been developed to detect mining cycle parameters such as setting and final pressures and duration of the cycle from these data for the analysis of periodic roof weighting phenomena. The intensities and persistence of periodic roof weighting are vital information for mine management to make judicious decisions on longwall operation.

By S. D. F. Rocha, A. L. A. SANTOS, E. M. A. BECHELENI, F. P. C. Silvas

Hydrometallurgical processes are needed to extract nickel (Ni) when it is disseminated in mineral matrix. High-pressure acid leaching (HPAL) and atmospheric acid leaching (AAL) are alternatives, and AAL has the advantage of requiring mild temperatures and pressure. Reducing-reagent tests improved the extraction of metals for the specific limiting portion of the ore. Low dosage of sodium thiosulfate presented better selectivity and safer operating conditions, allowing metal extractions of 50–62 percent at 95 °C. However, the low extraction rate obtained for Ni and the similar levels of impurities — magnesium (Mg), manganese (Mn), cobalt (Co) and iron (Fe) — extracted may represent economical and technological challenges in the downstream process.

By Deepak Malhotra, Linda Battich

INTRODUCTION Mineral processing plants generally operate efficiently within the technical, economic and management constraints applied to them. They have no choice, because the dynamic and competitive nature of the mineral business dictates that survival and/or prosperity of the company depends on being a low cost producer. Progressive mineral companies realize that market downturns will occur, and they must continuously strive for lower unit production costs rather than be satisfied with the status quo. Mineral companies generally tend to reduce costs during market downturns. This short-term solution is achieved by high grading of ores, and cut-backs In waste stripping, exploration, and capital expenditures.(1) However, to remain a low-cost producer in the long term, companies must enhance revenue and reduce cost simultaneously. This Involves continuous evaluation of technologies and reagents, periodic audits to locate revenue losses; and gathering and analyzing statistical plant data to clearly understand the Impact of process variables on efficiency. Mineral companies are caught in a Catch-22. They need resources to accomplish the objectives outlined above. Most mill stuffs have been cut to the minimum level necessary to maintain production. Resources such as time, manpower and money are scarce, and mill metallurglsts struggle to use these resources productively. Is your flotation plant optimized? History Indicates that successful operations constantly tune the flotation circuits to Improve metallurgy or reduce cost. This Is the essence of evolutionary change In mineral processing operations. A plant auditing approach can play a key role in assisting the process engineers to achieve the overall objective of enhancing metallurgy and reducing cost with limited resources through evolutionary improvements. FLOTATION SYSTEM The flotation process is the most widely wed concentration process In the world today. The number of variables that can affect the flotation results Is very large, maybe over 100. These variables can be divided Into three main groups: (2) (1) ore and mineral properties; (2) reagent treatment; and (3) flotation machine characteristics. Some of these variables can be controlled while others have to be accepted. Recently, Investigators (3,4) have attempted to describe the flotation process as an engineering system which includes chemistry, equipment and operating variables. Though some of the variables are Independent, most are co-dependent. thus making it difficult to develop simple cause and effect relationships. For example, it is easy to understand the effect of reagent change on recovery and grade In the rougher circuit, but very difficult to quantify Its impact on filtration downstream. Plant audits on a periodic basis are necessary to develop an understanding of the Interactive nature of the system. Auditing provides comparisons of plant operating performance before and after variable changes. OVERVIEW OF PLANT AUDITING An audit Is a formal, thorough and periodic examination of a system. There are various types of audits (i.e., geological, environmental, metallurgical. economic, etc.), and each serves a different purpose. (5) The discussion here is related to plant and/or metallurgical audits. Neale and Flintoff note that two key factors governing changes In an operation are: (1) the opportunity must be recognized; and (2) the justification for change must exist. (6) Both factors emphasize the critical role of successful plant auditing. Without plant audits. many opportunities for improvement must go unrecognized. On the other hand, when a situation ripe for improvement Is recognized. the hard data from a plant audit can reveal the expected impact of an operating change.

Jan 1, 1993

By Kenneth A. Rogers, Richard F. Hill

Introduction A number of processes for deriving more convenient liquid and gaseous fuels from coal are commercially available or in final stages of development. Generally, synfuels from coal processes have efficiencies ranging from 50 to 70%. Considerable engineering design and development work are necessary to bring forth commercial plants using the various technologies-but technological breakthroughs are not expected or needed. Gasification While a variety of solids handling, gas contacting, and gas quality upgrading techniques may be employed in the various gasification processes, the primary goal is the same-to convert a sulfur-containing solid to an essentially sulfur-free gaseous product. The gaseous product may be a mixture of hydrogen and carbon monoxide with nitrogen. Definitions are not rigorous, but high-Btu gas is generally over 900 Btu/scf(33 534 kJ/m3) and low-Btu gas is generally below 350 Btu/scf(13 041 kJ/m3). Medium or intermediate gas falls between these values. High-Btu production is more difficult, as it requires additional upgrading of a low- or intermediate-Btu gas stream to produce a commercially acceptable product. The carbon/ hydrogen ratio is adjusted either by rejecting a portion of the carbon, increasing the hydrogen, or a combination of both. The chemical processing steps include production processing gas containing carbon oxides and hydrogen by the reaction of carbon and steam (gasification); reaction of hydrogen and coal to form methane (a hydrogasification process); reaction of hydrogen and carbon monoxide to produce methane (methanation); and the removal of impurities. The gasification processes share a number of common techniques. The coal received at the plant site must be further cleaned and crushed or ground before it can enter the gasifier. Conventional cleaning methods are used to remove extraneous materials such as metal, rocks, etc. For some processes the coal must be finely ground so it may be fluidized or entrained in a flowing gas stream. For other processes crushing and sizing only are required. Agglomerating coals may be pretreated by heating, mild oxidation with air, or other procedures to assure smooth gasifier operation and to avoid reactor plugging. Nonagglomerating coals Such as lignite and subbituminous coal normally do not require pretreatment. Feeding a solid material such as coal to a higher pressure reactor is a difficult task. Dry feeders using a series of pressurized lock hoppers, or wet systems in which a slurry is pumped into the reactor, are used. The gasification step is the heart of the process. Here, the solid feed material is contacted with synthesis gas (carbon monoxide and hydrogen). The coal is devolatilized and a portion of the fixed carbon converted to methane. The gas-solids contacting methods used include fixed beds, fluidized beds, moving beds, entrained beds, and free-fall systems. The gasification process, overall, is endothermic and the heat required to maintain reaction rates is usually supplied by burning a portion of the coal feed. External heat sources such as electric resistance heating, molten salt or solid heat carriers, and the introduction of a hot hydrogen stream also have been tested. Following the gasification step the particulate materials and heavy hydrocarbons contained in the reactor effluent are removed by a water quench and solids separation system. If low-Btu gas or synthesis gas is the desired product, the raw gas is scrubbed to remove carbon dioxide and sulfur compounds and then is used directly. However, if high-Btu gas is desired, methanation is necessary. In most gasification processes, the hydrogen content of the gasifier

Jan 2, 1980

By Alfred Weiss, Andrew E. Nevin, Thomas J. Neil, O&apos

As Edward E. Runyan, 1983 AIME President, in an interview excerpt in ME, June, p. 607, stated, "...the AIME Transition Committee has recom¬mended to the AIME Board that each Constituent Society be allowed the option of separate incorporation, whereby each could become its own separate legal entity." Background The American Institute of Mining Engineers (AIME) was formed in 1871 by 22 engineers in Wilkes-Barre, PA. Although originally a mining organization, it became a home for metallurgists, iron and steel industry people, and for the individuals in the expanding petroleum engineering profession. There are now four Constituent Societies: Society of Mining Engineers, located in Littleton, CO, 29,000 members; Society of Petroleum Engineers, located in Dallas, TX, 47,500 members; The Metallurgical Society, located in Warrendale, PA, 10,000 members; and Iron and Steel Society, located in Warrendale, PA, 6,500 members. Each of the four groups has grown and continues to serve the specific and/or diverse needs of its membership. As the needs and requirements of their industries and professions change, each of the Societies has perceived and initiated programs that serve their constituency rather than AIME as a whole. Therefore, each Society has recognized an increasing need for autonomy to better augment their own programs. An AIME Ad Hoc Transition Committee, with Robert Merrill, AIME Past President, as chairman, made a number of recommendations pertaining to AIME operations that were approved in October 1982 by the AIME Board of Directors. One of the recommendations was to endorse separate incorporation of the Constituent Societies on an individual-society-option basis. The AIME Board commissioned a task force of Constituent Society representatives to develop specific revisions to the AIME Certificate of Incorporation and the AIME Constitution and Bylaws. This was done to allow separate incorporation and to reflect the decentralized structure of the Institute. The SME-AIME Board of Directors subsequently approved the recommendation of SME Working Party #69 that SME pursue separate incorporation. Meanwhile, Working Party #69 continues to work with the other Constituent Societies and with the AIME Task Force on Reorganization to determine the form and substance of the separate incorporation. Why Incorporate? George Webster in The Law of Associations quoted Chief Justice Marshall's (1819) definition of corporation as: "A corporation is an artificial being, invisible, intangible, and existing only in contemplation of law. Being the mere creature of law, it possesses only those properties which the charter of its creation confers upon it, either expressly or as incidental to its very existence. These are such as are supposed best calculated to effect the object for which it was created." SME-AIME attorneys, Davis, Graham & Stubbs, have pointed out that the status of an organization operating as an unincorporated association is always unclear. At present, SME-AIME administers assets of almost $3.5 million (mainly property and inventory) but technical ownership and ability to enter into contractual relationships resides with AIME. However, the operation appears to outsiders (particularly those with whom SME-AIME does business) to be an independent operation which would be expected to be a legal entity in its own right. Advantages of Incorporation Liability. Because of legal ownership by AIME of all assets of the Constituent Societies, those assets are subject to the claims of any of the creditors of AIME or any of its constituent parts (i.e., the other societies). Liabilities can be those usually encountered in business but also encompass special risks, which could develop if there were a careless and erroneous publication of material that might be used in practice or if standards are improperly established. The recent US Supreme Court decision in American Society of Mechanical Engineers, Inc.,

Jan 10, 1983

By J. R. Frederick

Introduction In response to industry needs and requests, Joy Mining Machinery is aggressively evolving a "game changing" system of underground development mining machinery. This entry-development system (EDS) project is concentrated on providing clean, protected and ergonomic operator areas and a quantum leap in productivity. To meet these goals, a virtually continuous and automated mining system is needed. Operators must be able to efficiently and ergonomically perform required functions from a protected environment. Health-related issues, such as respirable dust and noise, must also be addressed. A new concept system of integrated face equipment, from the continuous miner to and including advancing the section belt and services, is needed. Phase I of the project was aimed at developing the bolting technology required. Through acquisition of Cram Australia and joint development efforts with Canyon Fuel Co., Joy now has this capability. The test platform, known as the Joy Multibolter, has successfully completed its trials at Canyon Fuel's SUFCo Mine (Fig. 1). These tests validated the bolting technology and operator protection and ergonomic issues. Phase II includes the development and testing of an integrated mining machine (IMM) capable of advancing a heading 1.5 m (5 ft) while simultaneously cutting a fullface width (single pass) and installing a complete bolt pattern. The IMM, unveiled at MINExpo 2000, incorporates the bolting technology of the Multibolter with automated full-face cutting. This machine was designed to meet Joy's stringent health, operator protection and 300m/d (1,000-ft/d) productivity goals. Phases III through V will include development of processes and integrated haulage, ventilation, power, material handling and section services advancing equipment. Processes and equipment developed will be designed for seamless integration into a complete entry development system. The focus of this paper is the new continuous miner (IMM) development, proposed testing and expectations for the EDS. The IMM is scheduled for commissioning and trials beginning in April 2001 at the SUFCo Mine. SUFCo Mine Canyon Fuel Co. is jointly owned by Arch Western Resources and the Itochu Corp. of Japan. It owns and operates three coal mines in Utah: the SUFCo Mine in Sevier County, the Skyline Mine in Carbon and Emery Counties and the Dougout Canyon Mine in Carbon County. Incorporating state-of-the-art-mining technology and advanced mine management practices, the SUFCo Mine is one of the most efficient underground coal mines in the world. The SUFCo Mine is located approximately 50-km (30 miles) northeast of Salina, UT, in the Wasatch Plateau portion of the Uinta coal basin. The mine property consists of 9,900 hm2 (24,470 acres) with approximately 118 Mt (130 million st) of recoverable reserves. Public utilities and industrial concerns purchase approximately 95% of the coal mined at SUFCo through short- or long-term contracts. Coal reserves are extracted by longwall mining, and the panels are developed using continuous miners. The longwall face at SUFCo Mine is 283-m (930-ft) wide, and the seam height ranges from 2.4 to 4 m (8 to 13 ft). The two development sections are in full operation using Joy 12CM12 continuous miners. Two super longwall panels, under development in the northeast portion of the lease block, are 4,270-m (14,000-ft) long with a 283-m (930-ft) wide longwall face. Each panel contains approximately 5.4 Mt (6 million st) of recoverable coal. SUFCo has been a world leader in productivity for a

Jan 1, 2003

By YU. F. Vasyuchkov, K. Vasioutchkov, B. M. Vorobjev

Introduction It is now believed that, even with the environmental protection measures now being taken, the further application of traditional coal-mining and electric power-generation technologies will inevitably cause further irreversible damage to the global ecosystem. Further improvements in conventional coal-mining technologies, both surface and underground, are expected to have only limited impacts on the economical, ecological and social aspects of coal mining. In countries with a developed coal industry, coal reserves with favorable conditions at shallow depths are rapidly being depleted. Therefore, in the future, more coal will be mined from deeper levels, resulting in higher operational costs and lower labor productivity. The solution to this problem is to be found in developing, promoting and implementing unconventional coal-mining and advanced clean-coal technologies. This paper presents an unconventional concept that has been suggested by the authors. The basic goal is to achieve coal-methane energy resource conservation and to remove barriers to energy efficiency through the adoption of integrated, ecologically clean, innovative technology. The following principles form the foundation of this concept: Energy resource conservation: This principle concerns the exploitation of actual and potential coal-methane reserves in the most effective way with the lowest possible losses and with the application of the most energy-efficient electric power-generation technology. Energy conversion: Energy conversion means the conversion of solid coal to synthetic fuel gas (in situ or in-cycle), the conversion of methane bounded within the coal matrix to free-flowing drained meth¬ane, the conversion of solid coal in situ to a coal/water mixture (slurry), and the conversion of these gas fuels into electric power. Technological and managerial integration: This prin¬ciple means an integration of coal-gas methane min¬ing operations and electric power generation into one commercial mine-to-product enterprise with electric power as the final product. Thus, coalbed methane drainage and coal gasification (both in situ and in-cycle) integrated with a combined cycle of electric power generation constitutes a highly integrated coal-gas methane energy-generation system. The system can be materialized in the form of a local integrated coal-gas electric power complex (LICGEPC). General features of the new concept The coal-gas-methane electricity concept is actually a synthesis of the following four technological components: Coalbed methane drainage. This technique and its utilization attained recognition after commercial operations were proven successful in the San Juan and Black Worriers coalfields in the United States. Worldwide, extensive field experiments and research-and-development activities are being carried out in the area of coalbed methane exploitation and utilization. Recently, coalbed methane drainage for power generation has been undergoing intensive research and development. At the Harworth Colliery in the United Kingdom, a combinedcycle power plant has been built that uses coalbed methane. The plant has an installed capacity of 15 MW Also, Germany, Australia, the CIS and China have conducted various experiments and industrial tests on the use of coalbed methane power generation. Underground coal gasification. Another unconventional technological approach is underground coal gasification (UCG). A number of semi-commercial, demonstration and pilot projects have been undertaken in Russia, the Ukraine, Uzbekistan, the United States, the United Kingdom, Italy and Belgium to demonstrate the technical and economical viability of coal gasification in situ. In Uzbekistan, the Angren coal-gasification station has been in full-scale commercial operation for two decades. The operation supplies a power plant with synthetic coal gas. Under sponsorship of the US Department of Energy's Morgantown Energy Technology Center, large-scale laboratory tests simulating coal gasification in situ were successfully completed by the

Jan 1, 1999

By Joseph Cervik

Common methods of controlling gob gas in U.S. nines are by means of ventilation of gob areas and gas drainage through surf ace boreholes. Costs of drilling surface gob holes increase as deeper coalbeds are mined. Where gob holes cannot be drilled because of topography, ventilation is the only means of control. Even then, sufficient air may not be available to dilute methane in the bleeder entries to acceptable levels. Thus, new methods of gob gas control need to be developed that are independent of surface topography, and of the mine ventilation system, and less costly than present systems. Except for slight variations in procedures and equipment, Great Britain, West Germany, France, Belguim, Poland, and Czechoslovakia use a common methane control method that is different from the system generally used in the United States, This Bureau of Mines paper reviews European mining methods, mining conditions, and methane control technology and discusses their applicability to U.S. mines.

Jan 1, 1979

By Colleen A. M. Gibbs

On July 30, 1979 New Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the decade-old National Environmental Policy Act went into effect. These new regulations replace approximately seventy different sets of agency regulations, providing some uniformity throughout the Federal government in the conduct of environmental reviews and preparation of environmental impact statements (EIS). This attempt by the Federal government at a general improvement in the preparation and quality of EIS's presents an opportunity for the mining industry to evaluate how the EIS process for mining proposals can be expedited. The environmental impact statement is often a key element on the critical path of a major mining project. Preparation of the EIS is ordinarily the responsibility of the Federal agency with primary decision-making authority over the project. Still, the proponent, i.e. the mining company, can play a major role in the process and have a major impact on the timeliness and adequacy of the effort. Typically, the Proponent will conduct (or will hire consultants to conduct) environmental baseline studies of, for example, air quality, wildlife, geology, water quality, vegetation and archaeology. These studies are then compiled into an environmental report and submitted to the agency. The agency verifies the data and incorporates them into the environmental impact statement.

Jan 1, 1979

By David D. Lambert

REE analyses of cumulate plagioclase from the PGE ore zone of the Stillwater Complex indicate that pressure fluctuations in the magma chamber acting on a single magma can- not be responsible for features such as the reappearance of Mg-rich olivine on the liquidus. The data is more consistent with a model involving multiple injection and mixing of geochemically distinct magmas. The PGE bearing sulfides of the J-M Reef are associated with such a re- appearance of olivine, indicating that the unusual location of the ore zone may be related to the addition of new magma, compositionally distinct from magmas that produced cumulates in the Ultramafic zone of the complex.

Jan 1, 1981

By Francois E. Heuze

Excavation of large rock caverns is a stepwise process. Whether one uses a heading and bench method or a multiple drift system, the use of excavation steps enables one to introduce the reinforcement, such as bolts or shotcrete, at the earliest possible stage. Knowing the spatial distribution and properties of rock materials and geological discontinuities, the cavern geometry and its reinforcement must be optimized. The finite element method of analysis is a powerful tool for such optimization. However, the models are only as good as their ability to account realistically for the physical attributes of the prototype and for the excavation sequence. They must include the following: - ability to model an incremental construction process. Thus requires the use of "Restart" procedures where displacements and stresses from a previous equilibrium are saved for the next step. - ability to model non-linear rock material behavior; in particular, the post-peak behavior of the rock which retains a residual strength when con-fined. The stability of many under-ground structures rests with the "broken" rock carrying significant loads. - ability to account for the non-linear behavior of geological discontinuities. These are two-fold. First, up to peak, non smooth rock joints will dilate. In a confined situation, dilation will increase joint strength by a consider-able amount (Obert, et al, Brady, 1971, Heuze,1978a), Then, beyond the peak, the joint also retains residual strength.

Jan 1, 1978

By J. Guzman

Introduction The Carlin Trend is North America's premier gold producing district. It is located in northeastern Nevada's Elko and Eureka Counties along a northwest trending belt about 65 km (40 miles) long and 8 km (5 miles) wide (Thorstad, 1989; Jones, 1989). This trend is the worldwide reference site for epithermal, sedimentary rock-hosted microscopic gold deposits. At least 19 deposits have been discovered to date, varying in size from 933 kg to 1.08 kt (30,000 to 35 million contained oz) of gold (Fig. 1). Newmont Gold Co. and its parent, Newmont Mining Corp., jointly constitute the largest mineral right holders in the district. They own or control more than 1000 km' (386 sq miles) in and around the Carlin Trend and own all or part of I6out of the 19 mines and prospects identified to date. Since the initiation of Newmont's exploration activities in the Carlin Trend in 1961, 2.24 kt (72 million oz) of cumulative gold resources have been identified. Cumulative production from all mines since the start-up of Newmont's Carlin mine in 1965 to the end of 1989 was about 202 t (6.5 million oz) (Jones, 1989). The incentive of sustained high gold prices and innovation in processing technology resulted in a significant acceleration of gold output over the last few years. Newmont Gold alone produced more than 43.5 t (1.4 million oz) in 1989. That is equal to 22% of the cumulative 1965 to 1988 output, and an almost 200% increase over its 1986 output. The same incentives produced even more spectacular exploration results. In each of the last five years, net additions to reserves and resources outpaced current production by substantial margins. These facts demonstrate the spectacular past prospectiveness of the Carlin Trend and the success of focused, multi-disciplinary exploration methods that made it possible to more than offset the recent accelerated depletion of gold resources. However, is this situation sustainable? How long can the mining companies along the Carlin Trend keep on finding resources faster than they deplete them? These are some of the questions that motivated this study. The authors have not quantified the future potential for gold exploration in the Carlin Trend nor established a deposit discovery path. But strong indications were discovered that the [ ] Carlin Trend remains a relatively immature exploration district and that the potential for significant new discoveries is high. Methodology and data The approach chosen to address the above questions was simple. The authors compiled deposit size data, measured in contained ounces of gold resources, for all known deposits along the Carlin Trend (Table 1). The resource information was obtained by adding cumulative historical production (adjusted for mining losses and metallurgical recovery) to 1989 year-end published resource inventories. In a mature exploration area, where most deposits have been discovered, this distribution would be expected to approximate lognormality and would plot along a straight line on a lognormal probability scale. This result was found in previous work by Allais (1957) and recently confirmed by Cox and Singer (USGS, 1986) in regard to various types of mineral deposits in several regions of the world. It was also found to hold true for oil and gas pool size distributions (Arps and Roberts, 1958; Kaufman, 1962; McCrossan, 1969). [ ] The data used were compiled by Newmont Exploration geologists. The purpose of the study is to make inferences about the underlying geologic processes in the district and the maturity of the exploration effort. Therefore, deposits were not classified according to ownership but according to geologic occurrence as known from current information. Newmont's Post and Barrick's Goldstrike and Betze deposits, for example, are shown as a single occurrence to reflect the actual geologic setting. The cumulative frequency distribution of deposit sizes was plotted on lognormal probability paper (Fig. 2). The abscissa shows the cumulative fraction of deposits at or below a certain deposit size and the ordinate shows the deposit size in thousands of ounces of contained gold resources.

Jan 1, 1992

By Don Suttie, Frank Roybal, John Wright

The Roybal Raise incorporates the simplicity and low cost of a short bald-headed raise while overcoming the usual impediments to driving a high baldheaded raise. The concept provides for speedy excavation and maximizing the use of the excavated opening, using the rock for structural support. The design is simple: two baldheaded raises are driven parallel to one another, interconnected by dogholes about 8 m (25 ft) apart. In this fashion, the raise can be driven safely and efficiently to 60 m (200 ft) or more. When the raise is complete, the excavation requires no timber for support or partitioning. Rather, the rock itself supports the construction. As a test, a two-compartment Roybal Raise was attempted at the Independence mine in the Willow Creek District of Alaska. One side was driven 2 x 2 m (6 x 6 ft), intended for a manway and equipment skip. The other was driven 1.5 x 1.5 m (5 x 5 ft) for a muck compartment. Both sides were driven at a 65° angle from horizontal and 1 x 1 m (4 x 4 ft) dogholes spanned the 4.6-m (15-ft) pillar between the two compartments. After topping out at 50 m (160 ft), the raise was found to meet all expectations of efficiency, low cost, and practical simplicity. Technique Preparing the Roybal Raise for driving involves no elaborate or costly site prep except assembling materials and providing for muck removal. Normally, the raise muck falls directly onto the sill or track and is picked up either by an overshot mucker or a front-end loader. Raise mining proceeds initially by taking up both compartments simultaneously to the first doghole. It progresses by alternating one side as a clear manway for access with the other side, the active side, as a muck compartment (Fig. 1A). This stage proceeds quickly for no mucking or staging is required to cycle the first three rounds. On the fifth round, in addition to the normal raise round, rib holes are winged out toward the adjacent raise, thus starting the dogholes. Finally, as the sixth raise rounds are drilled and shot, the first doghole is also completed from both sides. The second stage commences by establishing one side as a clear manway for access while the other side, used as a muck compartment, is prepared for active mining. Figure 1B illustrates this step in the succession of raising with the active side advancing to the second doghole level. During this stage, services are maintained through the manway side and equipment is stowed in the doghole during blasting. As the active side advances, muck may be allowed to fill the bottom portion of that side since it is unnecessary to clear it for access. The next stage of raising involves cleaning out the former muck compartment and preparing it for use as a manway. At the same time, the former manway is prepared for advance and use as a muck compartment (Fig. 1C). As in the previous step, the same doghole is used for access and equipment storage. The active side advances until the second doghole is completed, at which point equipment and access are moved to the new doghole. From there, the active side is driven past the second doghole 8 m (25 ft) more to the third doghole level. Again, half of the doghole and the next raise round are mined. The fourth stage involves switch ing back the manway side for the muck side (Fig. ID). The new muck side is driven to the third doghole where equipment storage and access are reestablished. From there, the active side is advanced to the fourth doghole. In the same fashion, the raise is advanced to the top, alternating the manway side with the active side, maintaining access through the inactive manway, and storing equipment in the uppermost doghole. The cycle time for driving each compartment, regardless of the raise height, is greatly improved over that for normal bald-headed raises of comparable height. By storing equipment in the upper-

Jan 1, 1984

By E. J. Garrison

Discussion by E.J. Garrison A.C. Noble presents a clear and concise summary of the factors pertinent to a competent reserve evaluation of a mineral occurrence. However, I believe that he confuses the difference between a resource and a reserve. By definition, a reserve estimate includes all known economic, legal, mining, metallurgical and environmental factors impacting the recovery of the product(s) found in the deposit. A resource estimate, however, is an estimate of what is there - what is available for exploitation and should not include economic and other considerations. Only after defining the resource, its extent, location, physical and chemical properties, can an intelligent selection process begin of the extraction and processing technologies most appropriate to the circumstances encountered. The early and almost certainly inappropriate application of these often cookbook choices has probably lead many companies to walk away from good properties. (How many mines have been found in others rejects?) An example of the process is the early selection of metallurgical samples, after encouraging values are found in a few holes or surface samples, in an attempt to determine the economics of the prospect. Unfortunately, the sampler does not know how representative of the occurrence the sample is because he does not know what the deposit looks like. As a consequence, the property becomes saddled with a bad metallurgical sample that is often inappropriately used in evaluating the deposit which it does not represent. Reply by A.C. Noble E.J. Garrison asserts that I confuse the difference between a resource and an ore reserve. In fact, this paper was motivated by the observation that resources and reserves are almost universally confused throughout the industry. While Garrison is concerned that too-early consideration of engineering, metallurgical and economic factors will result in dropping properties too soon, some issues that must be considered include: •The purpose of exploration is to discover ore reserves, not to discover resources. •Ore reserves are always smaller than resources. • Decisions on exploration expenditures must be made based on the expectation of the quantity of ore reserves that will ultimately be defined. Noble's Fig. 2 can be used to give guidance as to when it is appropriate to begin reserve calculations. When exploration enters the "flat" portion of the curve, representative samples can be selected for metallurgical studies and appropriate mining methods chosen. It is at this stage that we know enough about the deposit to make intelligent choices of representative samples and recognize constraints on mining caused by the deposits shape, environment and physical properties. Once the appropriate technologies have been chosen, then their cost can be estimated with reasonable accuracy. Early entry of economic and process factors gives the false appearance of reserve status to the resource estimation. It would be more informative and less subject to abuse and misunderstanding if resource calculations were made at a number of cutoff grades. The cutoff grades should be chosen to cover the range of grades found in practice in existing operations of similar type. This would emphasize the open nature of resource estimates and encourage creative evaluation of mining and process technologies. It does not preclude the use of economic, environmental and recovery technology factors in deciding the advisability of continuing exploration expenditures, but would highlight their speculative nature. It is thus hoped that decisions on the future of the deposit would not be made on the presumed suitability of a given technology but on the actually known reality. I agree that resource estimates should be reported as a range of cutoff grades. Since reporting at a cutoff implies application of underlying economics (even by analogy to similar properties), however, it should be clearly stated that resources do not consider economic, mining or cost factors, and that ore reserves will be substantially less. The dilemma of the explorationist is that until the continuity and limits of ore-grade mineralization have been established, it is difficult to make quantitative estimates of either resources or ore reserves. Further industry discussion is needed regarding standards for disclosing early exploration information in such a way as to fairly represent the potential of an exploration property.

Jan 1, 1995

By Kanaan Hanna, Mir Heydari, Dipack Sengupta, Gordon B. French

This article concludes a two-part series on the safety, technology, and economic impact of eliminating safety fuse from metal and nonmetal mines. Discussed are the consequences of fuse abolishment, the technical feasibility of changing to an alternative system, and an economic analysis of initiation systems. Last month, part one (ME, pages 31-35) described current use of initiation systems, incidence of accidents, and consumption values for safety fuse and other initiation systems. Consequences of Fuse Abolishment Cap and Fuse Manufacturers Two major safety fuse manufacturers, Ensign Bickford and Apache Powder Co., share the US fuse market. Marketing of Ensign Bickford safety fuse is done by Dupont. Dupont manufactures electric caps as a main product and recently introduced a new nonelectric initiation system (Detaline). Therefore, Dupont would be only slightly affected by the elimination of safety fuse from metal and nonmetal mining. Ensign Bickford, though a larger manufacturer of fuse, does not appear to emphasize the safety fuse market. In fact, safety fuse sales represent only about 10% of Ensign Bickford's total sales volume. Ensign Bickford is strongly pushing its Nonel product. It appears, therefore, that the elimination of safety fuse would have a limited effect on Ensign Bickford, and could ultimately be to the company's advantage. Apache Powder Co., however, would be seriously affected if safety fuse was eliminated. Safety fuse, although not its only product, constitutes a major source of revenue for the company. It currently does not manufacture a substitute product. Apache Powder Co.'s manager agrees that prohibiting the use of safety fuse would result in a greater market share of initiators for Ensign Bickford. Hercules could also benefit from the prohibition of safety fuse. Metal and Nonmetal Mining Industry According to an explosive company contact, elimination of safety fuse by a mandatory regulation would force some of the small, marginal mines out of business. Another powder company representative believes that eliminating safety fuse will result in uneasy situations for small operators not familiar with other techniques. These operators try to minimize the costs and traditionally like safety fuse. He believes that insufficient proof exists to substantiate the overall safety increase if the fuse is eliminated. Fuse manufacturers and distributors disagree, then, about the impact of safety fuse elimination. However, they tend to agree on some important points: • Safety fuse can be a safe method if applied properly. • Electric blasting can be dangerous due to stray currents, and may have higher misfire rates than safety fuse. • It is very difficult to compare the rate of misfires and partial round failures for different systems. This is due simply to the nonavailability of such data. In many cases, the misfires are not even reported to the shift boss, as required by regulations. • Safety fuse has high acceptance in certain applications, such as a face where Nonel or detonating cord are used, or in open-pit blasting. • The safety fuse industry appears to be phasing out on its own. It is expected that the fate of the safety fuse market will be similar to that of black powder. An investigation by Nitro Noble of Sweden "clearly states that the diminishing use of safety fuse has considerably reduced the accidents in Swedish mines." Mine Data Acquisition and Analysis As a part of the study effort, visits were arranged to 24 metal and nonmetal mines. In most cases, underground visits were accomplished. At least one drilling and loading operation was witnessed. The mines were grouped into four mining areas: Wyoming, Montana, Idaho; western Colorado and eastern Utah; Missouri; and southern Arizona. Of all mines visted, the safety fuse system was used in 11 mines, electrical system in seven, Nonel in five, and the Hercudet system in one surface mine. At each mine, the manager, foreman, and blasting crew were interviewed for information and opinions. Besides informal discussions with mine officials, a questionnaire was also filled out for each mine. Due to the extensive length of the information gathered, these data are not presented here.

Jan 2, 1984

By R. Edward Williams

The Spa1lation Process Because of the low thermal conductivity of many hard rocks, rapid heating of these rocks produces a thin surface layer in which the temperatures attain high values. Thermal expansion of this surface layer is constrained by the reminder of the still cool rock, and when stresses within the surface rock become high enough, the surface rock breaks away from the cooler rock behind it and flies or falls off as a thin flake called a spall. Then the next, newly exposed surface is heated, and the process continues. This process is the basis of spallation drilling. The hot gases from a jet burner provide the heat for spallation to occur, and their high velocity provides a scouring action that transfers heat to the rock and removes the spalls as rapidly as they form. Spallation is a process which works in very hard rock. It is dependent upon the thermal expansion coefficient and the thermal diffusivity of the rock but is also affected by any discontinuities in the rock. To date the efforts which have been made to evaluate the various rock according to their spallability has been minimal. As the success of this process is dependent upon the characteristics of rock it is expected that the study of rock mechanics will prove to be of greater value to this program than to the other mechanism for drilling and excavating rock. Commercial Uses of SPALLATION In the 19408s, the Linde Air Products Division of Union Carbide (UC 1 began developing spallation for use in mining taconite ore, which is presently the chief source of iron in the United States. In this work UC developed a jet-piercing tool that burned fuel oil with oxygen to produce spallation and contained mechanical cutters to remove rock that was not amenable to spallation. The UC jet-piercing machines have since produced about 40 million feet of shallow blast holes used for emplacing explosives in the taconite mines. During this work it was found that hole diameters could be increased by merely reducing the advance rate of the burners and that existing holes could be enlarged by making another pass through the hole with the same burner. The Browning Engineering Go. of Hanover, N.H., has developed a hand-held spallation burner to cut slots in granite. It has been used for a quarter of a century and is now standard equipment for quarrying granite throughout the world. This burner, which resembles a small jet engine oriented with its exhaust pointed downward, is the forerunner of a flame jet burner used to spall experimental holes in granite at maximum rates in excess of 100 ft/hr when operating in hard, competent granite. It uses No. 2 fuel oil, which is burned with compressed air. The system uses water to cool the burner and the exhaust gases. These gases, along with the steam produced from the cooling water, blow the spalls from the hole. Experimental Work Theoretical and experimental work has been accomplished by the Massachusetts Institute of Technology and the Los Alamos National Laboratory. This work is reported in Refs. (3) and (4). To verify the experimental results of this work laboratory scaled down field tests were conducted using two we1 1 characterized granites from quarries in Barre, VT and Westerby, RI, under defined heating conditions. In the laboratory tests a propane - oxygen heating torch was used to direct a flame at the granite surface and the spal 1 ing process was examined at various heating rates with a high-speed video taping system operated at 200 frame per second. This produced a time-lapse sequence where the onset of the spallation process was easily distinguished. Also the heat flux from the torch to a flat surface at various stand off distances and flows was measured. A similar set of tests was conducted using the more easily quantified and uniform heat source of a 1.5 kw GO2 laser. This allowed accurate

Jan 1, 1986